Arylsulphamino-alpha-naphthol sulphonic acids



Patented Sept. 27, 1932 UNITED STATES PATENT powering OF LEVEBKAUSEN, NEAR COLOGNE-ON-THE-RHINE, GERMANY, AS- a} V r ANILINE WORKS, IN 0., OF NEW YORK, N. Y.-,

ARYLSULPHAMINO-ALZPHA-NAPHTHOL SULPHON ACIDS in Drawing. a l cation filed November 1, 1929,

The present invention relates to a process of preparing arylsulphamino-alpha-naphthol sulphonic acids.

In accordance with the tially pure arylsulph honic acids a caustic alkali upon arylsulphaminonaphthalene sulphonic acids containing least two sulphonic acid groups, at least one of them standing in an alpha-position of the naphthalene nucleus, at a temperature above about 120 C.

The reaction may be performed, for instance, by introducing the arylsulphaminoinvention substanamino-alpha-naphthol 11m or potassium hydroxide, advantageousthe presence of water, and then raising t e temperature above 120 0., preferably to a temperature between about 140-220 0., necessary with the application of superatmosp eric pressure. Th

then cooled, dissolved colored compounds,

free acids are soluble in alcohol, from which they are precipitated by the addition of Water.

The following examples illustrate my invention without limiting it thereto, the parts being by weight.

Example 1.l00

enzene sulpho chloride to about 0., and the reaction product is isolated by salting out.

ture is heated to about 0 minutes. The reaction mixture is then dissolved in water, acidified with hydrochloric are obtainable by reacting 'f e reaction mixture is- Serial No. 404,209, and in Germany November 6, 19.28-

acid, boiled up until no more sulphurous acid escapes, and the reaction product is isolated by salting out with sodium chloride. The acid sodium salt of 1-phenylsulphamino-8r naphthol-3.6-disulphonic acid having in its ree state the following formula OH macaw-O soan- -soan of greyishwhite soluble in water, 'difiiculty soluis thus obtained in form needles, easily blein alcohol. I

When starting in this example with 1-ptoluenesulphaminonaphthalene 3.6.8 tri 7 sulphonic acid, the corresponding p-toluenesulphomino-naphthol disulphonic acid of the formula: 4

( 11 lrIH-sm-O-Olh l i V V is obtained, having similar properties.

Example Z lOO parts of 1 zene-sulphochloride are added, whereupon the reaction mixture is heated to about 60 C. until a sample does not react anymore with sodium nitrite, care being taken that-the reaction mixture always y raised first to 130 C. and finally to 160 C. for 15 minutes, whereby the greatest part'of the water distills ofi. vAfter working up as described in Example I, a product having in its free form the probable formula A CORPORATION is obtained in form of greyish-white leaflets being easily soluble in water, difficulty soluble in alcohol. When replacing in this example the bengzene sulphochloride by p toluenesulphochloride, the, l-p-toluenesulphamino-8 naphthol-4e6-disulphonic acid will be obtained.

Example 3.1OO parts of Q-amino-naphthalene-6.8-disulphonic ac1d are dissolved in 1 200 parts of water and 10 parts of sodium carbonate and to this solution 60 parts of p-toluene-sulphochloride are added. The reaction mixture is then heated to 60-7 0 C. until a sample does not react any more with sodium nitrite, care being taken that the reaction mixture always reacts weakly alkaline.

240 parts of sodium hydroxide are then added and the reaction mixture is heated in an autoclave for about 8 hours to 180-200 C. After cooling the reaction mass is acidified with hydrochloric acid and the potassium salt of the 2-p-toluenesulphamino-8- naphthol-G-sulphonic acid is precipitated by the addition of potassium chloride.

In the above. examples other arylsulphamino-naphthalene-sulphonic acids, such as hydro-Ky carboxylic-acid-nap thalene sulphonic acids, benzylsulphamino-naphthalene sulphonic acid, naphthalenesulphaminonaphthalene sulphonic acids and the like may be used with a similar efiect.

I claim V 1. Process which comprises reacting upon an arylsulphaminonaphthalene sulphonic acid containing at least two sulphonic acid groups, at least one of them standing in an alpha-postion of the naphthalene nucleus with a caustic alkali at a temperature between about 140 and about 220 C.

2. Process which comprises reacting upon an arylsulphaminonaphthalene sulphonic acid containing at least two sulphonic acid groups, at least one of them standing in an alpha-position of the naphthalene nucleus with a caustic alkali in the-presence of water at a temperature between about 140 and about 220 C. V

3. Process which comprises reacting upon a compound of the formula SOiH wherein m stands for hydrogen or the methyl group, one y means hydrogen and the other the sulphonic acid group, with sodium hydroxide in the presence of water at a temperature of about to about 160 C.

Ho=s NH-S o O HOiS with sodium-hydroxide, in the presence of water, at a temperature of to G.

5. The process which comprises reacting upon a compoundof the formula:

H038 NH-SOOCH:

s0311 with sodium hydroxide, in the presence oi:

water, at a temperature of 140 to 160 C. 85 In testimony whereof, I aifix my signature.

CARL DOBMAIER. 

